A fully functioning Comprehensive nuclear-Test-Ban Treaty (CTBT) is essential for a world free of nuclear weapons. To measure radionuclides in the atmosphere in accordance with the CTBT, facilities such as SAUNA uses double coincidence techniques to discriminate between interesting Xenon isotopes. In this paper, a Monte-Carlo code (open source) based on first principles simulating a radionuclide detector has been built to investigate the viability of triple coincidence methods for measurements of $^{131m}$Xe, $^{133m}$Xe, $^{133}$Xe and $^{135}$Xe and found that by measuring $\beta - $ Ce $-$ X-ray coincides in $^{133}$Xe and $^{135}$Xe one could seperate the 30 keV photon energy region of interest by as much as $42.9 \pm 26.8$ keV and $214 \pm 50.8$ keV away from the original electron $-$ photon energy axes measured in SAUNA, using concentrations of Xenon isotopes typical for a nuclear weapons test one day after testing. The conclusion is that triple  coincidence  is  a  viable  method  for  nuclear weapons detection in light of double coincidence methods,  if only considering this  theoretical  approach.   No  conclusions  on  the  practicality  of  triple  coincidence methods in a CTBT could be drawn from these results.